Sorry if I put this question here but this board is looked at more than the Trans. board.

My question is how often should I or how often do you guys change your trans fluid and your rear end fluid?

I've got about 40.000 miles on mine, is it time for a change?



thanks

 

trans every 15-25k miles. ditto for rear. no matter what fluid you run it's a good idea to stick to manufacturers service intervals. you can use oil analysis but it's probably cheaper just to maintain normal service procedures.

 

Danno is right on. I drain the transmission and axle every 15K. I don't drain the torque converter (probably should), but the five quarts of fresh oil should help fortify the remainder of the oil left in the trans. I've installed trans drain plugs on all my cars to make the task easier and cleaner. The posi axle should get drained every 15K under severe service, as defined by the owner' and factory service manual. "Severe" is the way most of us drive, even if we don't push the car hard. 15K also seems to be about the time that the rear clutches in the Borg axles start to get noisy and need some fresh friction modifier. The newer style lockers don't require the additive, but anything with a cone-type clutch should have it. "Regular" or newer locker axles can go to 30K before service.

I just spent the better part of the day yesterday doing a 30K service on a van - two axles (one of them posi), transmission, transfer case, fuel and other filters, body/chassis lube, brakes, PCV, belt, etc.

Another note on Saginal (now callerd American Axle and Driveline) differentials - make sure the replacement cover gasket you install has the holes for oil return on the outer edges near the axle tubes. The factory gaskets don't, but the FelPro replacemetns have the holes. I'd rather keep my wheel bearings as long as possible.

 

Hmm!....well I guess im going to have to change the fluids.. hey does GM make a trans pan with the drain plug? I have seen a couple on EBAy but was wondering if GM has them for the 700r4 like I got....


also I need to fix an axle seal on the drivers side of the rear so that when I'll do the rear end fluid....


I think that job is going to suck...cause with my luck it wont go back together...and then Im screwd and stuck...

 

Wish,

If your '87 had the Borg axle, the outer seal is very easy, since there is no retainer clip in the differential carrier to hold the axle in place. It's more like the older Saginaw axles, where the axle retention is solely on the bearing retainer plate. Just remove the brake rotor and four bolts for the retainer plate - out comes the axle. Unfortunately, the bearing will have to come off to replace the seal, so you might plan on a new bearing before you start. Line up a shop with the bearing, seal, and a pres to remove/install it before you begin so you're not left scrambling for a shop with no means of transportation. If you do have a Borg axle, the cover is sealed with RTV, not a gasket.

As for the trans pan plug, if you have an oxy/acetylene torch at your disposal, you can install a drain plug easily. I use the replacement 1/2-20 drain plugs with nylon washers that you can find anywhere. Weld or braze a 1/2-20 jamb nut or 12ga plate into the bottom of the pan at a location that won't interfere with the valve body, then drill/tap a 1/2-20 hole for the plug. Repaint the burned area of the pan, then reinstall it with a new strainer (filter) and gasket. Mine cleared everything in this location:

 

VADER, its good to see your still on here. You have given me some good info in the past.

I have a 10 bolt 273 with drum brakes. I have no idea if it a borg or what....some told me that I have to drain the rear end and then take some C-clip out....whats your take on it?


do they make a 10 bolt cover with a drain plug?


The reason I think I have to replace the seal is because when I take my drum off there is fluid all on the inside of the drum. it doesnt look like brake fluid and I cant see the leak coming from the wheel cylinder theres none around it....plus I did replace both about a year ago....

Also when I hit my brakes my rears lock up...some said that because theres fluid around the drum it acts like a glue and makes them grab instead of not grab at all like we would think..

 

If you have a 10-bolt, then you have the C-clip design.

They do make covers with drain plugs; most all of the stud girdle type ones have them.

If your seal leaks, most of the time it's because the bearing is bad; and since the axle is the inner race for the bearing, that means it's probably bad too. When you decide to tackle the seal, make sure you have the other parts on hand, so you're not left scrambling - on foot - to come up with them.

Axles should look completely smooth and flat where the bearing rides on them, there should be no groove or step or anything else.

They also make "repair" bearing & seal assemblies, that change the inner race to a discrete object instead of being the axle... sometimes it's easier to use those than it is to find axles.